Field of the Invention
The present invention relates generally to noise and flash suppressors for firearms, particularly rifles, and more particularly concerns suppressors that are specifically designed to minimize the presence of residual propellant gas within a suppressor and rifle bore when the auto-loading mechanism of an auto-loading rifle initiates extraction of a spent cartridge case from the cartridge chamber of the rifle barrel. Even more specifically, this invention concerns minimization of the potential for residual propellant gas blow-back toward a firearm user by enhancing the volume of controlled discharge of propellant gas from noise and flash suppressors so that little if any residual propellant gas pressure is present within a firearm barrel at the time of cartridge case extraction by the auto-loading mechanism of a propellant gas energized firearm.
Description of the Prior Art
A significant number of firearm noise suppressor devices and flash suppressor devices, generally referred to as suppressors herein, have been developed over the years for use with firearms such as rifles and handguns. In most cases the suppressors are attached to the barrel of a firearm, such as by threaded attachment. In some cases suppressors are constructed integrally with a firearm barrel so as to be a permanent component of the firearm.
Typically, a suppressor comprises an elongate tubular body that attaches in any suitable manner to a firearm barrel and provides for the movement of a projectile from the bore of a firearm barrel and through the tubular body of the suppressor. To facilitate noise and flash suppression a number of internal baffles are typically positioned in stacked relation with baffle partitions disposed in axially spaced relation and with central openings in each baffle partition for projectile passage. A number of chambers that are defined between the internal baffles, causing the propellant gas to progress in serial fashion through each of the chambers. The partitions of the baffles are designed to reflect propellant gas and cause gas agitation within the chambers to slow the progress of gas transition through the suppressor and increase the dwell time and reduce the noise of the gas being exhausted from the suppressor. Propellant gas emitted from the bore of the barrel enters the much larger volume of the internal chamber of the tubular body and progresses in serpentine manner from chamber to chamber, with the gas expanding and its pressure being diminished within each successive chamber.
Suppressors are typically manufactured with threaded components which permit assembly and disassembly for cleaning of internal residue fouling and other service. When a suppressor device is releasably attached to a firearm barrel, repeated firing of the firearm typically causes continuous fouling of the baffles, chambers and threads of the suppressor by accumulation of cartridge powder residue. Thus, when the threads of the suppressor or the threads of a firearm barrel become fouled it may be difficult or impossible to remove clean and reassemble the components of a suppressor device. This undesirable characteristic is common to most types of suppressors and represents a distinct disadvantage when working with the firearm during field conditions. It often becomes necessary to return the firearm to a repair or service facility to clean away cartridge powder deposits. It is desirable therefore, to provide a suppressor mechanism that effectively ensures isolation of the threaded connections that secure the suppressor components in assembly and at the same time provide for effective stability and durability of the suppressor mechanism and its connection with a rifle barrel.
Another disadvantage of firearm suppressor use is the problem of suppressor instability and the potential for coaxial misalignment that results from the use of a threaded connection of the suppressor to the barrel of a firearm. The barrel of a firearm that is designed for attachment of a muzzle brake or suppressor is typically provided with a reduced diameter externally threaded section that is of fairly short length. An internally threaded section of a typical suppressor attachment end wall is fairly short, thus causing the threaded connection to have minimal stability due to the typical length of the threaded connection of the suppressor with the firearm barrel. It is desirable to provide a suppressor mechanism that is exceptionally stable as well as protecting the internal threaded components from the undesirable characteristics of gunpowder residue buildup and fouling. U.S. Pat. No. 8,511,425 of Mark C. LaRue shows a suppressor device that employs a flash hider type fitting as a structural interface with a tubular suppressor housing. The flash hider structure shown in the '425 patent has spaced, angulated external support surfaces that are in engagement with corresponding spaced internal surfaces of a housing mount. This feature adds materially to the structural integrity of the coupling mechanism for securing a suppressor to the threaded end of a firearm barrel.
Typical firearm noise suppressors have multiple compartments within a single elongate, typically cylindrical tubular housing and define a single gas flow path. The baffles that are spaced within the suppressor housing create back-pressure within the suppressor that is relatively slow to be exhausted to the atmosphere. In many cases some residual gas pressure will remain within a suppressor at the time the auto-cycling mechanism of a gas energized firearm causes unlocking of the bolt member and begins to extract a spent cartridge case from the cartridge chamber of the firearm. When this condition exists a small amount of the residual propellant gas may be released from the bore of the firearm due to the back-pressure within the suppressor when unseating of a cartridge case begins, thereby directing a small amount of residual propellant gas toward the user of the firearm. The presence of propellant gas can be objectionable from the standpoint of the comfort of the user. It is desirable, therefore, to provide a firearm noise and flash suppressor that provides for enhanced propellant gas exhaust to ensure optimum discharge of propellant gas and minimum gas exhaust dwell time so that little if any residual propellant gas pressure exists within the suppressor and firearm barrel when spent cartridge case extraction begins.